/* Alloy Analyzer 4 -- Copyright (c) 2006-2009, Felix Chang
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

package edu.mit.csail.sdg.alloy4;

import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.util.Vector;
import javax.swing.Icon;
import javax.swing.JComboBox;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.ListCellRenderer;
import javax.swing.border.EmptyBorder;

/** Graphical combobox.
 *
 * <p><b>Thread Safety:</b> Can be called only by the AWT event thread.
 */

public class OurCombobox extends JComboBox {

   /** This ensures the class can be serialized reliably. */
   private static final long serialVersionUID = 0;

   /** This caches a preconstructed JLabel that is used for the rendering of each Combo value. */
   private static JLabel jlabel;

   /** Subclass can override this method to provide the custom text for any given value (or "" if no text is needed) */
   public String do_getText(Object value) { return String.valueOf(value); }

   /** Subclass can override this method to provide the custom icon for any given value (or null if no icon is needed) */
   public Icon do_getIcon(Object value) { return null; }

   /** Subclass can override this method to react upon selection change. */
   public void do_changed(Object newValue) { }

   /** This helper method makes a copy of the list, and then optionally prepend null at the beginning of the list. */
   private static Vector<Object> do_copy (Object[] list, boolean addNull) {
      Vector<Object> answer = new Vector<Object>(list.length + (addNull ? 1 : 0));
      if (addNull) answer.add(null);
      for(int i=0; i<list.length; i++) answer.add(list[i]);
      return answer;
   }

   /** Constructs a new OurCombobox object.
    * @param list - the list of allowed values
    */
   public OurCombobox (Object[] list)  { this(false, list, 0, 0, null); }

   /** Constructs a new OurCombobox object.
    * @param addNull - whether we should prepend null onto the beginning of the list of allowed values
    * @param list - the list of allowed values
    * @param width - the width to use (if width==0 && height==0, then we ignore this parameter)
    * @param height - the height to use (if width==0 && height==0, then we ignore this parameter)
    * @param initialValue - if nonnull it is the initial value to choose in this combo box
    */
   public OurCombobox (boolean addNull, Object[] list, int width, int height, Object initialValue) {
      super(do_copy(list, addNull));
      setFont(OurUtil.getVizFont());
      setRenderer(new ListCellRenderer() {
         public Component getListCellRendererComponent(JList list, Object value, int i, boolean selected, boolean focused) {
            if (jlabel == null) jlabel = OurUtil.label("", Color.BLACK, Color.WHITE, new EmptyBorder(0, 2, 0, 0));
            jlabel.setText(do_getText(value));
            jlabel.setIcon(do_getIcon(value));
            jlabel.setBackground(selected ? list.getSelectionBackground() : list.getBackground());
            jlabel.setForeground(selected ? list.getSelectionForeground() : list.getForeground());
            return jlabel;
         }
      });
      if (width>0 && height>0) { // Make some platform-specific adjustments which should make the combobox look nicer
         if (Util.onWindows() && height>25) height = 25; // Otherwise, the height is too high on Windows
         setPreferredSize(new Dimension(width, height));
         setMaximumSize(new Dimension(width, height));
         if (!Util.onWindows() && !Util.onMac()) setBorder(new EmptyBorder(4, 3, 4, 0));
      }
      if (initialValue!=null) { setSelectedItem(initialValue); }
      addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent e) { do_changed(getSelectedItem()); }
      });
   }
}
